Propofol-induced inhalation anaesthesia in dogs after xylasine or xylasine and midazolam premedication.

The objective of the studies was to compare the premedication with xylasine alone and a midazolam/xylasine
combination applied for inhalation anaesthesia induction with propofol. The studies aimed at determining
the effect of the examined anaesthesia methods on the animals physical condition, the acid-base balance
parameters and arterial blood oxygenation. The study was conducted on 48 male mixed-breed dogs aged from
3 to 11 years, of 5-25 kg body weight. The animals were divided into two groups. Group I was premedicated
with xylasine (2 mg/kg bw.) and atropine (0.05 mg/kg bw.) intramuscularly, and group II was administered
xylasine (1 mg/kg bw.), atropine (0.05 mg/kg bw.) and midazolam (0.2 mg/kg bw.) intramuscularly. In both
groups the premedication was followed after 20 minutes with propofol used for induction, given to effect
intravenously. General anaesthesia was conducted by administering a mixture of halothane and oxygen. Propofol
was shown to induce loss of consciousness in the animals premedicated with xylasine alone or a xylasine/
midazolam combination at the mean dose of 3.12 and 3.13 mg/kg bw. respectively. Premedication with singleagent
xylasine or xylasine in a twofold lower dose in conjunction with midazolam does not affect the propofol
dose required to induce unconsciousness. The administration of midazolam/xylasine preanaesthetics
compared to the premedication with xylasine alone suppresses vomiting as well as accelerates the recovery
and return of motor functions in patients anaesthetised with propofol.